1. Field of the Invention
The present invention relates to a prosthetic foot and more particularly to a prosthetic foot adjustable for use with shoes having heels of different heights.
2. Description of the Prior Art
The prior art includes prosthetic foot structures of a variety of types. One well-known type has a ball and socket ankle joint while another well-known type has a solid ankle. Both of these types utilize a cushioned heel and a flexible toe to simulate the action of a natural foot in walking.
An individual foot of these and all other prior art structures is proportioned and dimensioned for use only with a shoe heel of a predetermined height unlike natural feet which can, of course, adjust to heels of different heights. However, prior art prosthetic feet, lacking the elaborate and flexible structure of natural feet, cannot accommodate shoe heels varying substantially from the predetermined height to which they are individually adapted. When used with a different height of heel, prosthetic feet cause discomfort, require increased exertion by the user, and result in a clumsy and uneven gait.
Since each prosthetic foot is individually fitted to a prosthetic leg, it is necessary to provide a prosthetic leg and prosthetic foot for every height of shoe heel which will be worn by the user of such a device. This is inconvenient at best and is prohibitively expensive for most users of a prosthetic foot.
It has, therefore, long been recognized that it would be highly advantageous to provide a prosthetic foot which is adapted for use with shoe heels of varying heights and yet is relatively lightweight and sturdy.